Light is a form of electromagnetic radiation that consists of particles called photons. Photons can be emitted by hot, glowing objects such as stars, as well as by other energetic phenomena like nuclear reactions, cosmic rays, and even certain chemical processes. These sources of light are distributed throughout the universe, illuminating the vast expanse of space.
However, it is important to note that space itself is mostly empty, so light does not interact with anything in empty regions, making it appear dark to our eyes. But even in apparently empty regions, there can be faint background radiation, such as the cosmic microwave background radiation, which is the remnant glow from the early stages of the universe.
Furthermore, light can be absorbed, scattered, or blocked by intervening matter, such as interstellar dust, gas clouds, and even planets or other celestial bodies. This can cause regions of space to appear dark or obscured from our perspective.
In summary, while space may appear dark to our eyes in certain regions, light is abundant in the universe, originating from various sources and traveling through space to reach us.